Figure 1.

Impact of aging on neurovascular coupling (NVC) responses elicited by cognitive n‐back task in the prefrontal and motor brain cortices. All results are based on data from 21 young and 30 aged participants. In a representative young participant, A) the increase in oxyhemoglobin (HbO) during the 2‐back task exceeds the HbO rise in a representative aged participant. B) Shows the deoxyhemoglobin (HbR) changes; HbO and HbR records were obtained from the F4(source)‐F6(detector) channel belonging to the dorsolateral prefrontal cortex. Statistical contrast of HbO changes between the 2‐back and first 0‐back condition reveals significant NVC responses only for C) the young but not for E) the elderly group as indicated by the color‐coded t‐values with a cutoff at q < 0.05 (obtained after false discovery rate correction). For both age groups, D,F) localized changes can be seen for HbR changes between the same task conditions. Analyzing the effect of age on the contrast between 2‐back and first 0‐back condition revealed that HbO responses in prefrontal regions are significantly reduced (indicated by blue shades) in the aged group compared to G) the young group, but there is no notable difference for H) HbR responses. The standard channel positions in the current montage and the relation of the actual channel layout to the brain according to the 10–20 system were visualized by the AnalyzIR toolbox (Santosa, 2018); red and blue dots represent sources and detectors, respectively.